Attempts have been made to employ 1,1-disubstituted alkene compounds in a number of applications such as adhesives, coatings, composites and the like. 1,1-disubstituted alkene compounds are commonly known as methylene malonates. These compounds have been known since the 19th century and in the middle part of the 20th century a number of researchers worked with these compounds, see D'Alelio U.S. Pat. No. 2,330,033; Coover U.S. Pat. Nos. 3,221,745 and 3,523,097 Halpern U.S. Pat. No. 3,197,318 and Ponticello U.S. Pat. Nos. 4,056,543 and 4,160,864, all incorporated herein by reference in their entirety for all purposes. Despite this work the 1,1-disubstituted alkene alkene compounds have not been commercialized. The disclosed processes for the preparation of these compounds are equilibrium processes which i) also prepare a number of by-products that negatively impact the stability and reactivity of the desired products, ii) which can cause formation of undesired by-products, and iii) which can cause the formation of by-products which prevent reasonable use of the compounds. In addition, some of the by-products and starting materials are difficult to separate from the desired compounds. 1,1-disubstituted alkene alkene compounds polymerize at room temperature under mild conditions which render them both useful and present problems with their stability. The problems with the processes and the products of the processes were not fully appreciated until Malofsky et al. studied the compounds and processes and began developing ways to produce the compounds without the presence of starting materials and by-products that negatively impact their stability and began developing methods of enhancing the stability of such compounds while facilitating cure of the compounds at room temperature and upon demand, see Malofsky et al U.S. Pat. Nos. 8,809,885; 8,884,406; US20140329980; and US 20150073110; all incorporated herein by reference in their entirety for all purposes.
The work of Malofsky et al. resulted in commercial interest in 1,1-disubstituted alkene compounds for use in a variety of applications. For many uses the 1,1-disubstituted alkene compounds prepared in the Malofsky et al patents and applications provide advantageous properties and processes.
Many of the 1,1-disubstituted alkene compounds prepared in the Malofsky et al. patents and applications have limited combinations of one or more physical property (e.g., glass transition temperature(s), melting temperature(s) (if any), viscosity, molecular weight, molecular weight distribution) and one or more mechanical property (e.g., tensile properties, elongation at break, impact properties, elastic modulus, shear modulus, adhesion properties, and elastic recovery properties). For a limited number of applications these properties are advantageous. To broaden the application for these compounds it is desirable to develop polymers including one or more 1,1-disubstituted alkene compounds with different molecular architecture and/or different combinations of monomers. Similarly, there is a need for polymers and polymerization processes for achieving a combination of polymerization rates with physical and/or of mechanical properties.
For example, there is a need for polymerization methods, systems, polymerizable compositions, and resulting polymers that allow for improved control of one or more of the following properties of a polymer containing one or more 1,1-disubstituted alkene monomers: the weight average molecular weight, the number average molecular weight, the polydispersity index, the zero-shear viscosity of the polymer (e.g., at one or more temperatures of at least about 20° C. above the melting temperature of the polymer), the viscosity of the polymer system (e.g., the bulk polymer melt or the polymer emulsion) at room temperature, the sequence distribution of monomers in a random copolymer, having at least two different polymer blocks covalently bonded (e.g., each, containing one or more 1,1-disubstituted alkene compounds), the glass transition temperature(s) and/or the number of glass transition temperatures, the crystallinity (if any), the melting temperature (if any), the adhesion to substrates (e.g., lap shear strength, breaklose torque), the reaction rate (e.g., the setting time of a composition including the monomers), the tensile properties, the impact properties, or the long chain branching.